1. Field of the Invention
This invention relates to connecting devices, and more particularly to connector devices for connecting well tools or pipe to relatively thin-wall tubes, such as, for instance, reeled or coiled tubing.
2. Description of the Prior Art
Coil tubing, also known as reeled tubing, has been used in the oil industry for many years. Coiled tubing is often forced into wells through use of a coil tubing injector so that fluids may be circulated down the coil tubing and upward through the well for such purposes as removing sand bridges or other deposits which may plug the well tubing or otherwise hinder the flow of production fluids through the well. It is well known to attach well tools to the distal end of a coil tubing for performing various operations downhole in a well, for instance, using cleaning tools which direct high pressure, high velocity streams of water or other liquids against the wall of the tubing or casing to clean the same, or using well tools which utilize pressurized fluid conducted to them through the coil tubing, or using the push/pull forces applied thereto through the coil tubing to accomplish work as may be required in locking or unlocking, or dislodging tools and/or flow control devices in a well or for actuating well tools requiring such forces for their operation.
It may be desirable in some cases to rotate coil tubing in the well to perform operations such as drilling out sand bridges or the like with bits or similar tools which require rotation. Rotation of coil tubing requires that it be severed and that a connector be attached thereto so that the coil tubing in the well is then connectable either to pipe or reconnected to the coil tubing remaining on the reel.
Of course, whatever tool is used on the lower end of the coil tubing in the well must be securely attached thereto by a suitable connector. While connectors have been used for connecting various tools to coil tubing, or the like, applicant is aware of none which will reliably transfer sufficiently great torque loads in addition to great tensile loads while at the same time withstanding great fluid pressures.
The following patents appear to relate to coil tubing and the attachment of tools and devices thereto, and are hereby incorporated into this application by reference. U.S. Pat. Nos. 3,401,749, 4,091,867, 4,515,220, 4,516,917, 4,518,041, 4,612,984, 4,682,657, 4,685,516.
U.S. Pat. No. 3,401,749 which issued to W. L. Daniel on Sept. 17, 1968 shows, in FIG. 6, a conduit 24 attached to a jetting head 26 by what is obviously a thread.
U.S. Pat. No. 4,091,867 which issued to Frederick E. Shannon, Jr. and Tibor Lakey on May 30, 1978 teaches a system and apparatus for injecting a flexible hose into a well under pressure, the hose 22 being composed of sections joined together by couplings 25. (See FIG. 1 and column 3, lines 16-23.)
U.S. Pat. No. 4,515,220 was issued May 7, 1985 to Phillip S. Sizer, Don C. Cox, and Malcolm N. Council and discloses two different connectors for connecting pipe to the upper end of coil tubing which is to be rotated in a well as for drilling out sand bridges, or similar operations. One of the connectors, shown in FIG. 4, is welded to the coil tubing and provides a pipe thread for receiving the pipe. In FIG. 5 there is illustrated a non-welded connector having slips for gripping the coil tubing and a thread for receiving the pipe. The end of the coil tubing is notched or slotted and a pin in the connector is engaged in the notch or slot, thus enabling the connector to transmit torque loads. Understandably, this pin/notch arrangement is not likely to transmit very great torque loads.
U.S. Pat. No. 4,516,917 which issued to Carlos R. Canalizo on May 14, 1985 discloses a gas pump attached to the lower end of a coil tubing, this connection being accomplished through use of a hydraulic type connector 34c commonly known as a LENS Fitting. Such fitting is not meant to transfer high torque loads.
U.S. Pat. No. 4,518,041 which issued on May 21, 1985 to Casper W. Zublin shows a jet type cleanout tool attached to coil tubing as in FIG. 2 and as by a thread mentioned at column 5, lines 22-24.
U.S. Pat. No. 4,612,984 which issued to James B. Crawford on Sept. 23, 1986 teaches a connector for connecting wireline tools and the like to the distal end of a coil tubing. This connector provides two load transfer surfaces which are spaced apart longitudinally. The first of these two transfer surfaces is a thread and the other is a plurality of set screws tightened against the outer wall of the coil tubing a spaced distance above the thread.
U.S. Pat. No. 4,682,657 issued to James B. Crawford on July 28, 1987 and is a division of his parent application which matured into U.S. Pat. No. 4,612,984 just discussed. U.S. Pat. No. 4,682,657 whose drawing is identical to that of U.S. Pat. No. 4,612,984 teaches methods for running tools in wells on coiling tubing.
U.S. Pat. No. 4,685,516 which issued to Lonnie J. Smith, et al. on Aug. 11, 1987 teaches apparatus for operating wireline tools in well bores. The tool is connected to the lower end of a coil tubing 28 by a connector 84, the coil tubing 28 having its lower end portion disposed in bore 140 of the connector and is secured therein by a plurality of set screws 139. (See FIG. 5A, and the specification beginning at column 6, line 12.)
Also, Applicant is familiar with a brochure entitled "PYPLOK Pipe Connecting System" published by DEUTSCH Metal Components Division, Gardena, Calif., which shows and discusses a connector for connecting conduits together and may also be useful in connecting coil tubing to coil tubing or to various tools and devices.
There was not found in the prior art a connector for connecting well tools, or the like, or pipe, coil tubing, or the like, which could transmit relatively high tensile and torque loads and withstand relatively high pressures.